At the present time, the technique of low-elevation tracking radars is showing a trend toward two-band radars. The low-frequency band (I-band, for example) permits correct tracking down to a predetermined angle of elevation above the horizon. In the case of angles of elevation which are smaller than this predetermined value, a higher-frequency band is adopted (W-band, for example), thus producing a much narrower beam.
However, in the prior art, sources respectively operating in these bands are separated, thus giving rise to difficulties in regard to coincidence of the radiation axes and resulting in unsatisfactory operation of the system.